It is not the extension cord that that is dangerous it is the moron that does not read the package that the cord comes in. Most ACs draws a full 20 amps of currant when the compressor hicks in to start cooling. A 100 foot length can only carry a bought 8 amps enough to run one fan on one AC. LOOK ON THE PACKAGE REQUIREMENTS for amperage draw. That said the camper manufacturer supplies a 30 or 50 amp cord depending on the campers usage most of them are sized by gauge and length to properly supply the campers usage. The breaker on the panel box will shut off (the safety mechanism that some people override). This is not rocket science.